1. The Field of the Invention
The present invention relates to distillation. More specifically, the present invention relates to a method and system for distillation which provides improved results in distilling mixtures which are difficult to distill. Additionally, the present invention provides a method and system which are effective in treating used oil, and which are effective in producing fuels such as diesel fuel from used oil including used motor oil. The present invention further provides an apparatus and methods for improving production and efficiency at an oil well.
2. The Background Art
Currently, used oil is undesirable as it has limited use. The processing and refinement of used oil including used motor oil has been limited to filtering the oil through a screen, dewatering the oil, and selling the oil as burner oil. Such a process is certainly advantageous over disposal of the oil, but has several limitations.
Used oil typically contains a significant amount of contaminants such as motor oil additives, ash, metal particles, sulfur, etc. Such impurities typically make it more difficult to use the oil as a fuel. These impurities may increase the emissions released from burning the oil, as well as making it more difficult to operate the burner. Additionally, burner oil is inexpensive and as such it would be advantageous if the used oil could be converted into a move valuable product such as diesel fuel instead of simply using the oil as a burner oil.
Several problems have prevented the refining of used oil to produce diesel fuel or other refined products. One problem is that the used oil contains significant impurities such as ash, metals, motor oil additives, etc. which are not easily removed from the oil. Such impurities may be undesirable if present in a refined oil product, and may impede the refining process, such as by inducing coking inside of distillation vessels. Another problem encountered in refining used oil (which are black in color) is that when distilled into the appropriate cuts, the fuels (diesel typically distills as a light amber liquid even from used oil) and products thus distilled are unstable and quickly oxidize and turn black again, and are generally of inferior quality.
There is thus a need for a method and apparatus which overcomes the limitations of available refining processes. Specifically, there is a need for a method and apparatus for refining and distilling difficult to separate mixtures, and in particular there is a need for a method and apparatus for refining used oil to produce fuels and usable oil which are stable and of quality comparable to fuels distilled from virgin crude oil.